Thanks everyone for the suggestions.  The laptop definitely is stereo.
Earlier this evening (Thursday) I disconnected the fibre optic cable
between the monitor and the amplifier.  I then plugged in a pair of
cheap earphones into the monitor and played some music. Only one ear
received any sound.

It looks as though the HDMI cable is the culprit.  The next step is to
connect another HDMI cable between the laptop and the monitor. That I
will do tomorrow morning (Friday).

Regards, Ken Heard
   I
---
Post to this mailing list talk@gtalug.org
Unsubscribe from this mailing list https://gtalug.org/mailman/listinfo/talk